Two days after a massive mudflow inundated the Dharali village in Uttarkashi, experts are still looking for an answer to pinpoint the exact reason behind the tragedy that has led to at least five deaths and over 60 missing.

While the verdict is out on the cause of the tragedy, experts are cautioning on why it led to such extensive damage, with hundreds of buildings struck, buried under the debris of mud and boulders.

The loss of life and property could have been exacerbated by encroachment in the riverbed of the Bhagirathi River, according to Prof. K Sheshgiri Rao, a renowned geology expert and Emeritus Professor at the Indian Institute of Technology Delhi.

Prof. Rao, who was travelling through Rudraprayag, explained that the region experienced heavy rainfall continuously for three to four days, which likely triggered a massive mudflow that struck Dharali.

RIVEBED ALTERED

While mountainous regions often face natural hazards such as cloudbursts, glacier lake outburst floods (GLOFs), and monsoonal mudflows, he emphasised that the scale of destruction seen in Dharali was amplified due to human intervention in the river’s natural course.

The encroachments and constructions within the riverbed altered the flow dynamics, and when the powerful mudflow struck the built-up areas, it collided with buildings with immense thrust and force, causing catastrophic loss of life and property.

The width needed for the mudflow to pass was missing due to construction in and around it, which worsened the disaster.

The professor posed critical questions about why constructions in such vulnerable riverbed zones were allowed, highlighting the consequences of unchecked urbanisation driven largely by tourism development in the region. This unplanned expansion into ecologically sensitive and disaster-prone zones has increased the risk exposure of local communities.

SATELLITE DATA REVEALS EXTENT OF DAMAGE

Supporting these observations, recent satellite analyses performed by Suhora Technologies, using Synthetic Aperture Radar (SAR) and high-resolution optical imagery, revealed the extensive impact of the Uttarkashi disaster.

The data, captured at 11:01 PM on August 5, showed approximately 148 buildings damaged and an area of about 16 hectares affected. The imaging also highlighted damage to critical infrastructure, including one bridge and nearly 0.95 km of roadway, leading to significant disruptions in connectivity and emergency response.

The Uttarkashi tragedy highlights the urgent need to regulate and enforce land-use policies to prevent encroachment on riverbeds and other high-risk zones.

It also calls for sustainable urbanisation practices that respect the natural dynamics of mountainous ecosystems to mitigate loss and enhance community resilience against future disasters.

As rescue operations in flood-ravaged Uttarkashi entered the third day on Thursday, the Indian Army confirmed that 70 people have been rescued so far, while more than 50 remain missing.

Efforts are being intensified to airlift advanced equipment to Dharali village—one of the worst-affected areas—to aid in locating those still trapped under debris, officials said.

The Army, working in close coordination with local authorities, has scaled up Humanitarian Assistance and Disaster Relief (HADR) efforts in Dharali and the nearby region of Harsil. Both areas remain largely cut off due to extensive landslides and multiple road breaches caused by the flash floods.

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